Injection Site Pain Is Main Adverse Event for Gardasil

ATLANTA — Injection site pain is the most frequently reported adverse event following receipt of the quadrivalent human papillomavirus vaccine, Dr. Lauri Markowitz said at a meeting of the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices.

Through January 2007, the passive Vaccine Adverse Event Reporting System (VAERS) has received a total of 542 reports associated with Merck's quadrivalent human papillomavirus (HPV) vaccine (Gardasil), of which 5% were considered serious. No deaths were reported, said Dr. Markowitz of the CDC's National Center for HIV, STD, and TB Prevention.

A total of 2.1 million doses of Merck's HPV vaccine had been distributed through December 2006. The adverse event reporting rate, 25/100,000 doses, is slightly higher than that seen with other vaccines but “not unexpected for a new vaccine,” she noted.

Injection site pain was the most commonly reported adverse event (18%), followed by dizziness (11%), syncope (11%), fever (9%), and nausea (9%). More than 99% occurred in females, reflecting the population for whom the vaccine currently is recommended. Nearly half (47%) of those reporting adverse events were aged 13–18 years, and another 38% were aged 19–26 years. Only 7% were aged 9–12 years, 6% were over 26 years of age, and the rest were less than 9 years.

There were three reported cases of Guillain-Barré syndrome (GBS), two of whom had simultaneously received the meningococcal conjugate vaccine (Menactra) 9 and 13 days earlier. It was not known whether the third GBS case had received other vaccines at the same time. An association between Menactra and GBS has been reported, although it is not yet clear whether the relationship is causal (MMWR 2006;55:1120–4).

Facial palsy was also reported in three cases, all within 1 day of receiving Gardasil. Two of those individuals had received influenza vaccine—one live attenuated and one inactivated—at the same time. The background rate of facial palsy in the general population is 30/100,000 per year.

“We can confidently say that the observed [rate] is much less than expected,” Dr. Markowitz commenteted.

Physicians are encouraged to report all clinically significant adverse events in patients following receipt of vaccines to VAERS, online at www.vaers.hhs.gov